1. Field of the Invention
The present invention relates to a waveform generation device and, more particularly, to a waveform generation device for use with an electronic musical instrument, which is so adapted as to read and reproduce waveform data of various sounds and voices stored in a memory.
A such waveform generation device can be used for such an electronic musical instrument called, for example, a sampler.
2. Description of the Related Art
Heretofore, a waveform generation device is generally arranged to vary a waveform reading velocity, i.e. a velocity of reading clocks, from a memory, in accordance with a reproducing velocity of reproducing the waveform by making the reproducing velocity faster or slower than a recording velocity (a recording time) for recording an original waveform, upon reproducing the recorded waveform. This technique, however, suffers from the difficulty that a pitch of the reproduced waveform has changed from that of the original waveform.
In order to solve the difficulty prevailing in the such conventional technique, there has been employed techniques which utilize a time stretch technique for waveform data. The techniques involve subjecting waveform data of a memory to compressing or expanding in accordance with a reproduction time and reproducing the waveform data previously formed with the time stretched. The techniques, however, require performing the process for the time stretch previously, so that it has the problem that it cannot be controlled optionally at a real time. Further, it suffers from another difficulty that the reproduction time is also caused to vary when the reading velocity for reading the waveform data is varied in order to change a reproduction pitch of the waveform data that has been subjected to the time stretch processing. The conventional time stretch techniques as described hereinabove present the problems that the compression of the time axis and the change of the pitch cannot be controlled independently from each other and at a real time.
Further, another technique has been proposed to solve the problems involved in the conventional techniques, which is concerned with a process comprising changing a reproduction time by changing a reading velocity for reading a waveform from a memory and correcting the change of a pitch of the reproduced waveform resulting from the change of the reproduction time with a pitch conversion device. This technique can control the reproduction time at a real time, however, a conversion capability of the pitch conversion device is so low and the reproduction time to be controlled is restricted to a very narrow range. In particular, it may cause inconveniences when the reading velocity of reading a waveform is to be made slower.
This pitch conversion device has further the problem that the original waveform data cannot be reproduced, for example, in instances where the reading velocity of the memory is made slow to perform a control using a long reproduction time.
Furthermore, such a technique suffers from the difficulty that it requires a very complicated control when it is intended to perform the control of the reproducing velocity (reproduction time) and the control of the reproduction pitch independently from each other, because the pitch conversion device causes its volume of the pitch conversion to change when the reading velocity is changed.
Moreover, in a usual case, conventional pitch conversion devices simply reproduce waveforms successively at a waveform reading velocity corresponding to a pitch to be reproduced. Hence, when an instruction to stop the reproduction is issued, then the waveform reproduction is stopped in the position in which the instruction was issued. Likewise, when an instruction to resume the reproduction is issued, then the waveform reproduction is resumed from the top position at the waveform reading velocity corresponding to the pitch specified at the start time. This type of the reproduction processes simply creates a so monotonous expression of performance.
In order to solve the problems involved in the conventional techniques, the present invention has an object to provide technology that can optionally change a reproducing velocity and a pitch of a waveform at a real time.
Another object of the present invention is to provide technology that can realize the effect of a new expression and provide performance and so on rich in expression, which can stop and resume the development of the reproduction of a waveform, for example, in a syllable unit or jump to a syllable to come next.
In order to achieve the objects, in an aspect of the present invention, there is provided a waveform generation device which comprises a storage means for storing waveform data of a waveform sequence with plural waveforms arranged in time series; a pitch information input means for entering pitch information concerning a pitch; a time information generation means for generating time information concerning a time varying with a changing velocity having no connection with a reproduction pitch; and a reproduction means including a read means for reading waveform data in correspondence with the pitch information and the time information, the read means being for reading the waveform data from the storage means at a reading velocity and having no connection with a changing velocity of changing the time information, and the reproduction means being for reproducing the read waveform data at a reproduction pitch corresponding to the pitch information of the pitch information input means.
In the waveform generation device in this aspect of the present invention, the reproducing velocity for reproducing a waveform sequence is determined on the basis of the changing velocity of the time information of the time information generation means and the changing velocity of the time information has no connection with the pitch. Thus, the reproduction means allows an independent adjustment of the reproducing velocity of the waveform sequence and the reproduction pitch when the waveform data is read in correspondence with the time information and the pitch information, at the reading velocity having no connection with the changing velocity of the time information and the resulting waveform data is reproduced at the reproduction pitch specified by the pitch information.
The waveform generation device may be further provided with a first control information input means for entering first control information for changing the changing velocity of the time information; wherein the time information generation means has a means for changing a changing velocity of the time information in accordance with the first control information to be entered. The first control information may be generated or issued, for example, by the operation of a time companding operation unit for setting a value in advance or a modulation lever or the like to be operated at a real time.
Further, the waveform generation device may have the time information generation means composed of a counter which is configured so as to change its stepping volume on the basis of the first control information.
With the arrangement of the waveform generation device in the manner as described hereinabove, the changing velocity of the time information can be changed by the first control information to be entered by the first control information input means in the manner as described hereinabove, thereby capable of optionally changing the reproducing velocity of the waveform sequence. In this case, too, the reproduction pitch is not changed by the reproducing velocity.
The waveform generation device in this aspect of the present invention may further be provided with the read means which is so configured as to read a waveform segment containing a waveform of at least one cycle of a position indicated by the time information in a cycle corresponding to the pitch information and at a reading velocity having no connection with the changing velocity of the time information and to convert the waveform data into the reproduction pitch with a formant retained therein.
This arrangement of the waveform generation device according to the present invention can reproduce the reproduction pitch, with the formant properties retained herein as they are, by reading the waveform at the same velocity as when the waveform is sampled, as the reading velocity for reading the waveform segment containing a waveform of at least one cycle.
Moreover, in this aspect, the waveform generation device of the present invention may be provided with the read means which has two processing systems; in which each processing system is configured to generate a waveform of at least one cycle of the waveform data at a cycle corresponding to a two-fold length of the reproduction pitch and then to convert the waveform data of the waveform segment into the reproduction pitch by eventually adding output from the two processing systems to each other.
The waveform generation device in this aspect of the present invention may further be provided with the formant change information input means for entering the change information for changing the formant of the waveform of the waveform sequence; in which the read means is so configured as to perform the control to make the reading velocity for reading the waveform data of the waveform segment slower when the change information is information to shift the formant thereof to the low region side and to perform the control to make the reading velocity of the waveform data thereof faster when the change information is information to shift the formant thereof to the high region side.
With the arrangement of the waveform generation device, the formant of the waveform to be reproduced can be shifted to the higher region side or to the lower region side by entering the change information by the formant change information input means.
In another aspect of the present invention, there is provided with a waveform generation device which comprises a storage means for storing waveform data of a waveform sequence with plural waveforms arranged in time series; a reproducing velocity information input means for entering a reproducing velocity information representing a reproducing velocity of the waveform data; a pitch information input means for entering a pitch information; and a reproduction means for reproducing the waveform data of the storage means at the reproducing velocity corresponding to the reproducing velocity information and at the pitch corresponding to the pitch information; wherein the storage means stores the waveform data and a mark information indicating one or more positions of the waveform sequence on a time axis; and the reproduction means has a first control means for performing a control for controlling a movement of a reproduction position of the waveform data when the reproduction position of the waveform data has reached the position indicating the mark information.
The waveform generation device in this aspect of the present invention can adjust the reproducing velocity and the reproduction pitch of the waveform independently from each other. In addition, the movement of the waveform reproduction can be stopped in the position indicated by the mark information, for example, the position of each syllable.
In a further aspect of the present invention, a waveform generation device comprises a storage means for storing waveform data of a waveform sequence with plural waveforms arranged in time series; a reproducing velocity information input means for entering reproducing velocity information representing a reproducing velocity of the waveform data; a pitch information input means for entering pitch information; and a reproduction means for reproducing the waveform data of the storage means at a reproducing velocity corresponding to the reproducing velocity information and at a pitch corresponding to the pitch information; wherein the storage means stores the waveform data and a mark information indicating one or more positions of the waveform sequence on a time axis; a second control information input means for entering a second control information for controlling a movement of a reproduction position is provided; and the reproduction means has a second control means for performing a control for controlling a movement of a reproduction position of the waveform data when the reproduction position of the waveform data has reached a position indicating the mark information in accordance with the second control information and for releasing a controlled status in which the movement of the reproduction position of the waveform data is controlled.
The waveform generation device in this aspect of the present invention can adjust the reproducing velocity and the reproduction pitch of the waveform independently from each other. As the second control information input means can give an instruction to stop the development of the reproduction position of the waveform and to release the stop of the development thereof in the position indicating the mark information, the player can control the development of the segments of the syllables at a real time, for example, by allowing the position indicating the mark information to comply with the segment of the syllable. This can add a rich expression to performance or the like.
In a still further aspect of the present invention, there is provided a waveform generation device which comprises a storage means for storing waveform data of a waveform sequence with plural waveforms arranged in time series; a reproducing velocity information input means for entering reproducing velocity information representing a reproducing velocity of the waveform data, a pitch information input means for entering pitch information; and a reproduction means for reproducing the waveform data of the storage means at a reproducing velocity corresponding to the reproducing velocity information and at a pitch corresponding to the pitch information, wherein the storage means stores the waveform data and a mark information indicating one or more positions of the waveform sequence on a time axis; a third control information input means for entering a third control information for controlling a movement of a reproduction position is provided; and the reproduction means has a third control means for performing a control for jumping a reproduction position of the waveform data to a position indicating the mark information in accordance with the third control information for controlling the development of the reproduction position.
The waveform generation device in this aspect of the present invention can adjust the reproducing velocity of the waveform independently from the reproduction pitch. As the third control information input means can give an instruction to jump the reproduction position of the waveform to the position indicating the mark information, the player can control the development of the segments of the syllables at a real time, for example, by allowing the position indicating the mark information to comply with the segment of the syllable. This can add a rich expression to performance or the like.
These and other objects, features and advantages of the present invention may become apparent in the course of the description that follows, with reference to the accompanying drawings.